add _gtk_tree_view_column_get_editable_cell and

add _gtk_tree_view_column_get_editable_cell and

Sun Apr 14 16:56:59 2002  Kristian Rietveld  <kris@gtk.org>

        * gtk/gtktreeprivate.h: add _gtk_tree_view_column_get_editable_cell and
        _gtk_tree_view_column_get_neighbor_sizes

        * gtk/gtktreeviewcolumn.c (struct _GtkTreeViewColumnCellInfo): add
        real_width field,
        (_gtk_tree_view_column_get_editable_cell): implement,
        (gtk_tree_view_column_cell_process_action): fill info->real_width
        (_gtk_tree_view_column_get_neighbor_sizes): implement

        * gtk/gtktreeview.c (gtk_tree_view_button_press): make the "editable
        widget" show up with the same size as the actual cell, so it doesnt
        cover the complete column if there are any other cells in that column.